Forming a passageway through tissue may be necessary in order to position an interventional medical system for delivery of therapy or diagnostics within an organ or the circulatory system of a patient. Typically the passageway is formed, via an apparatus that includes a needle, dilator, and introducer sheath, such as is known to those skilled in the art of interventional medical systems. Although a variety of configurations for this type of apparatus are known in the art, there is still a need for new configurations, for example, new configurations that are useful in forming a passageway that facilitates the delivery of an implantable cardiac pacing device.